1. Field of the Invention
The present invention relates to a liquid crystal drive device, a LCD apparatus and a drive method.
2. Related Art
In general, when a motion picture is displayed on the LCD, motion picture blurring occurs because of poor response characteristics of liquid crystal. In order to improve this, a technique for improving the response speed of the LCD by contriving a drive method has been developed (U.S. Pat. No. 7,106,286).
In the motion picture display, an area where an image does not move and an area where an image moves occur in many cases. In the still area where the image does not move, clear display is obtained because there is no motion picture blurring. In the motion picture area where the image has moved, the image looks blurring. Therefore, an edge detection enhancement drive technique of detecting an edge of an area where an image has moved by using the technique for detecting an edge area and applying stronger enhancement to the detected edge area is developed (USP Application 2006/0066554A1, or M. Baba et al., “Software Processed Edge-Level-Adaptive Overdrive Method for High-Quality Motion Picture,” SID 05 Digest, pp. 1942-1945). Denoting an enhancement coefficient by α, an enhancement correction coefficient in an edge part by β, a gray scale level value of a preceding frame by L0, a gray scale level value of the current frame by L1, and an enhancement drive gray scale level value by LLAO, enhancement correction is conducted so as to satisfy the following equation in the ordinary enhancement drive method.LLAO=α(L1−L0)+L0 
According to an edge enhancement drive method described in U.S. Patent Application Laid-Open No. 2006/0066554A1, or M. Baba et al., “Software Processed Edge-Level-Adaptive Overdrive Method for High-Quality Motion Picture,” SID 05 Digest, pp. 1942-1945), enhancement correction is conducted so as to satisfy the following equation.LLAO=αβ(L1−L0)+L0 
According to the enhancement drive method using an edge detection technique described in USP Application 2006/0066554A1, or M. Baba et al., “Software Processed Edge-Level-Adaptive Overdrive Method for High-Quality Motion Picture,” SID 05 Digest, pp. 1942-1945), excessive enhancement is applied to a detected edge area and consequently ringing noise or the like is apt to occur, and favorable motion picture characteristics are not obtained in some cases.
In portable devices such as portable telephones, low power dissipation, size reduction of the device, and weight reduction are in great demand and it is demanded to reduce the size of the liquid crystal drive device as well.